Control apparatus for blow torch



June 7, 1960 J. P. KARPUK ETAL 2, 3 10 CONTROL APPARATUS FOR BLOW TORCH Filed June 17, 1954 4 Sheets-Sheet 1 INVENTORS nmam MbTIQBNEYW.

June 1960 J. P. KARPUK ETAL 2,939,410

CONTROL APPARATUS FOR BLOWII'ORCH Filed June 17, 1954 4 Sheets-Sheet 2 N P 8 JOH JESSE B.THOMAS ATTORNEY June 7, 1960 J. P. KARPUK ETAL I 2,939,410

CONTROL APPARATUS FOR BLOW ,TORCH Filed June 17, 1954 4 Sheets-Sheet s Limit Switch Thermo Limit Switch Limit Switch Flow Operated Switch Flg. 3

INVENTORS JOHN RKARPUK 8 JESSE B.THOMAS 'Qm'am ATTORNEY June 7, 1960 J. P. KARPUK ETAL 2,939,410

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An he ebieet is he e eieh e15 p a tu ter ,f d 1s enhtt otnae a j pewde ehd ees geh "he a h e torch which embodies automatic, eogtrol peeps for the s a t e PP h e hehee n, e e ehhe; the eeehr A he ehi if ieh pm i eh it e hh a atus w ich i l hte ehi ly we eee eh. e the teeeh ehehl the te e h h hdeh d hy the QPQFMQIT- h h a ara u K whi h t e pr nt ih eh i e relate met wher 1,? fed me etxe h 91 ex he e ehl eeeh z he he h' h ehe h: fit e. Pewde h ihs trehev zee r; len th 'ee gme m n 1E $214 the para us e m x n e mete Pe ee wv ih, e e e! w ing therefrom to the togeh 0 figh evex gt qt 5 h h ew-ied inte th ele 9. the e eeeh ih htieh in l e a e l 19 mehged *9 hu eff th flew t pe er ee eh he fle of U h re he e elo a Pr etee et e t h peeetuxe eeh e led s h 19 w f hy eh hel metal e der it th Water temper tux ee h h; n o y en r ehr imi e ite 9 hu e the hew '0? Ox g n d meta pews es the KY f v u hew er is e p d b th ene hteh. the fle hi o y e ie ma ic l 9h tinned e a eee etem heh time pr dete ined h to enable the operzito; to

h hee i e ff heiig res me op ra ion of the eieeieeeti 1.; eezeteneq terz exiQe-e mixin ehemher Qt.

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' Feer the h eih membe eemprieee t e 51fmhbl eehe met d. ef ehgle he and um: ed h e etere 51-. Ar hp ete. e ee n th h m hee h oeehine tee r ee ve i h p h! sui bly mee s; he eeve h 'hrae etehe hopper ie edj ted teeehte n where; aluminum m a or her ehh hle powde ed me e d we. is illed th u h a r mov b e eever, fish If. de hehte exe e re rel ef valve m he provided in the cover. e t v The ep h h em 9f t hep et hee e ee hx h fl n 55 fo; the opeq top of a fleectkerew houeipg 56. This houeigg 5Q hes {if ogeefid, a tubular pron'ectior; 57' pl oyidihg' edead end bore and, at the opposite epd, another'tubuler projection providing an' outlet bore,this latter-projection terminating in if T58. The housing 56 is silpported from the bottom'of the frahie 'by suitable postaileand contains at screw 59 extending p 3 from'the dead end bore of projection shaft 61 of the feed screw 59 extends from the feed screw through a stufling box 63 in one end of T 58, and is driven by a motor 64 through reduction gearing-65 coupled thereto by a coupling 66. Y 7

The outlet-T 58, of the feed screw housing 56, dlS charges into an outlet conduit 67 connected toa mixer 68. The mixer comprises a housing having a through flow passage 69 therein with an inlet bushing 71 at one end connected to an inlet-pipe 72 having a solenoid valve 72 therein (Fig. 4) and a reducing outlet bushing 57 through the housing 56 into the T 58 of its outlet bore. The drive to a predetermined maximum. The arrangementof these switches into the electrical operating circuit is illustrated in Figure 4.

Referring to Figure 4, the coil of master or main relay 113 is connected to electrical supply main 114 through a lead 115 which includes a self closing manually opened stop switch 116 and a self opening manually closed master starting switch 117. Relay 113 controls switch 113a,

73 at the other end connected to the conduit-73',- which in turn is connected to flexible conduit 4. Oxygen from a suitable tank or bottle 74 (Fig. 1) is conducted to inlet pipe 72' by a conduit 75 and as the oxygen passes through the mixer 68 it picks up and carries the pow-- d'h-d'bf dscrew59throuh... I qered alummum, lsc e y Ce 8 the pump develops enough flow to close the flow conduits 67,.through outlet conduits 73' and 3 to the torch where the aluminum is burned. From pipe 72' a branch connection 76 leads to adjacent the top of hopper 53; this connection being upstream from the mixer 68 to insure-a higher pressure in hopper 53 than in the mixer and prevent the powder being blown from the mixer back into the hopper. The dust in the hopper is kept-in a mobile orfluid condition by an electric hopper vibrator 89 of known construction'controlled' by a regulating knob'91 (Fig. 2) on a controller box 91' mounted in the housing.

A heat exchanger or radiator, 92 is mounted in -the 2 housing and carries ablower 93 operated by a motor 94. An accumulator tank 95 on the framecarries water, and is connected by a conduit 96 to the heat ex-1 113b and' 1130. A holding circuit for relay 113 is shunted around switch 117 and includes normally open water flow switch 111, normally closed water temperature switch 112, normally closed oxygen lowpressure limit switch. 107, normally ,closed hopper high pressure limit switch 109, relay switch'113a and holding lead 118. A lead 119 from' the main transformer to relay switch 113b connects by lead 120 to the water pump motor 94 so that, upon energizing relay 113, switch 113b is closed to start the pump. Flow switch 111 remains open until switch. Thus, upon manual closing of switch 117 the relay 113 isenergized, but upon release'of switch 117 relay'113 will not remain energized unless all switches I 111,112,107 and 109 are closed. That is, master starter switch 117 must beheld closed until 'the pump develops the required minimum flow to close flow switch 111, and thereafter upon release of this starter switch the relay 113 is held energized by the holdingcircuit.

. I Holding switch 113a is connected by lead 121 to' the changer. At the bottom, a conduit 97*connlects. the 13 heat exchanger 92 to a pump 98 which isdriven bymotor 99. Cooling water is conducted from the pump ;98 through the conduit "101 which connects-with flexible conduit 5 to the blowtorch -1. This water returns'from the blowtorch by way of conduit 6 which connects to conduit 102 and reenters the radiator 92 where it is cooled.

The operation of the apparatus so far describedwill be explained'in connection with Figure 3 whichgdiagrammatically illustrates the arrangement of the apparatus. The igniter fuel, which preferablyis acetylene gas, but may be any other combustible gas or liquid is .sup plied from tank or bottle 103 through a conventional reducing valve by a conduit 104 having a solenoid operated valve 105 therein. "This conduit 104 connects with the flexible conduit 4 connected to the torch ,1.

Oxygen gas is supplied from bottle 74 by conduit having the solenoid operated-valve 72 therein, and conduit 75 leads by conduit 72' to the mixer 68. From here the mixture of oxygen and metal powder is conducted by pipes 73' and flexible conduit 3 to the blowtorch. 'A conduit 106 branching from conduit 75 connects to low pressure limit switch :107 of suitableconstruction; The conduit 76 supplies pressure to the hopper from.

conduit 72, and a high pressure limit switch 109 is con-' nected to the hopper; These switches are normally closed. If the oxygen supply pressure falls too low, due, for example to exhaustion of-the oxygen bottle, the limit switch 107. is opened to shut valve 72 and stop the flow of oxygen to the torch as will be later explained. In

switch-111 is open. Temperature limit switch 112 is nornally. closed and opens if thewatertemperature igniter gas solenoid valve so that closing of switch 117 opens the solenoid valve 105 to start the How of isniter-gas to the torch. V 'j I Lead-114 extends from the transformer to'switch 113c and the circuit continues by lead 122 containing self open ing manually closed-setting switch 123, and by lead 124 to submaster relay 125. "Submaster relay '125"opera.tes two switches,125a and 125b, and from lead "122 a lcad 126'goes to switch 1255 which connects by a lead-12,7 to solenoid valve 72 which controls the oxygen flow It will be seen that after the holdingvcircuit of main relay 113 is energized, the closing or opening of setting switch 123 does not atfect the main relay, nordoes it affect the flow'of igniter gas. However, switch 123 energizes submaster relay 125 to start the flow of oxygen gas, and the flow of oxygen gas stops when submaster relay 1 25 isde-energized. A holding circuit for the submaster relay includes'leads 126, 128 to normally closed timer operated switch 129 of timer 130,"and'lead 131 to switch 125q and holding lead 132. That is, timer operated switch 129 is shunted around manual switch 123. Thus, upon closing normally open setting switch 123 the 'submaster relay 125 is energized, to close switches 1 25a'and 12512 and energize the oxygen valve '72 to start the flow of oxygen to the mixing chamber, and the closing ofswitch 125a completes the holdingcircuit of relay 125 so' that, upon release of switch7123 the submaster relay remains energized as-long as timer operated switch 129 is closed.

Connected to lead 127 is a lead 132' that goesto timer to start its operation upon closing of submaster relay switch 125b. Timer 130 is set to open time limit switch 129 at some predetermined time interval, as for example, thirty seconds and unless an intervening circuit is established, the opening of time limit switch 129 will decr ergize the holding circuit of submaster relay 125, which will open submaster switch 12512 to deenergize solenoid valve 72 and stop the flow of oxygen. The purpose of this will be later described.

Timer 130 is energized through relay switch 125k and leads' 127, 132'. Timer 133 is energized through switch 125b and leads 127, 132 and 134. At this point it should be mentioned that electrically operated timers 130 and 133 are of the self resetting type ofknown construction which do not reset until the supply cu r'rent fails. Thus, when timer 130 opens switch 129, the 'holding circuit of relay 125 is opened, so that relay 125 opens switch 12512 to"de'energize timers'130 and '133 to cause them to reset. Any desired type of timershe used,

.fQ s p rpos "The powder feeder relay 135 operates swi h S 13551 an i 1 '5 n ts he g i g i it hit'ihc udes' d s" 1. 2 1126. swit h '125 .'1 hd .2 3 134. 36. 1 1 crafted switch 137 (normally open), lead 138, mally open torch control switch 139 and'lead"140. Re1ay Switch 351 close t e he g zine li'rcuitsof e h wd ff der motor 64 and vibrator motor-. 9; which includes lead 141, Switch 1351?, and lead 142.

" Timer' 133 is energized by the "closing ,of switch .125!) at thesame time timer 130is'ener'giied. Ti mer 133 is set to close switch 137 after a predetermined time inte y l, for example, thirty -seconds, 'fbutwith a sli'ght lead (Preferably one second or less) .overtimeropened switch 129, so that switch 137 will be closed bytirne'r 133 a moment before switch 129 isopene'd by timer 130i Thus, torch operator switch 139 can energize relay 135.,tostart fth "feed of powder only if the switch 139 isfinfclosed position during the 'intervalbetween' the closing of switch .lllfl fand openingef ,switch129. If mien switch 139 iS not' heId closed during this interval the opening of switch'129'by timer 1'30 deene'rgize'sthe holding circuit of relay 125 as previously describedithii'sppeiiin}; switch 125blto deenergize oxygen valve wander venting energization of the operating circuit of re ay 135, an dresetting the timers 1 30, 133. This arrangementinsuresstopping the flowbf oxygen to the torch 'in the event the torch" is not putflinto operation in the prede- Itermined time set ,to open switch l29 aftertheflowof oxygen to thetorch begins: Toinsure that switch 139 closed at the proper "time, the operator should old "switch 139c l'osed during, or'inimediately after {the of switch 123. If switch l 39 fails to catch thiqroper time the s sls' hl b lii i l-t P sh closing the setting switch 123.v i V H A holding circuit, shunting switch 123, isjelosed1vvhen switch 139 is closed at the proper time] holding circuit includes a holding relay 143," operating switches 4 143a and 1435'. The closing ,of switch 139. at the proper time energizes relay 135, and the closing of switch 135a thereby sets up an energizing circuit for relay 143' through switch 125b, leads 127,132, 14 4,Svvitch 135a'and lead 145. The closing of this holding circuit keeps relay 125 energized, and renders ineifective .the opening ofitimer switch 129 in the holding circuit of relay 125. That is, switch 129 is substituted by relay 143.

From the description so far pursued it will be seen sle t-sees the as m rhtsh cl e itch 15 when the s hh t .1 Qthhfid itfi e c m th sh not h 1111 ow n t e' to 1h slowly i nt the piston opens iswitchLli-TOL {From lead 132 a lead 150' hihhemiip r 'yv t h 1 .0. nti t e 152 c n c thi swi c t sw c the t e at e i h i tu b ng teld y le d 1. .3 to le d 1 t Pr i e a h l in s shh ta re -1.1131 I h he c n o s it 150 izes a l, h .hi s ish hi for o en d 1 Relay 143Ohld be omitted, in which case lead 152 would'be connected from switch 150 to lead 147 and lead 145 frqm switch 135;; would go to switch 150. However because of the clamping action .of the dashpot 1 th r Wei- 1 he e ig a h h losi s h 139 until switch 150 would close, this lag might be suffi 'cient to deenergize solenoid 125 under some conditions. For this reason" it is preferred to employthe relay 143 so t a cl s ng of switch 139 im rriediately closes an operating 'circuitfor relay 12 5, and the closing of switch 150 en r z s th h ldi c rcuit ierjre e 1 Upon"openiiig switch 139 relay 1355 is immediately e n si ed t st th fl w of de a d a po is released. fi ter the predetermined time interval for which the dashpot is set, switch 15% opens to deenergize relay 143 and thus .dee'n'ergize relay. 125. However if withinthistime interval, while switch 150 is still closed,

that when switch 139 is closed at the proper-time, relay 135 closes to start the feed of powder to" the torch and also operates relay 143 to hold relay 125 energized. Thereafter, upon opening of switch 139, relay 135 is deenergized to stop the flow of powder, and in the circuit so far described, relay 143 also would be deenergized to deenergize relay 125 and stop the flow of oxygen. In this event, it would be necessary to start the torch by depressing switch 123 and holding switch: 139 closed for theihalf minute interval required by the timers 130, 133 to start the torch. It is desirable to allow the torch to be extinguished for a short time to new inspectionbf the work, without encountering the delay involved at the'start of the cycle. For this purpose, a delay means is provided to allow continued oxygen flow for a predetermined time 7 to purge the line, and permit immediate resumptionof hh s el t rte T el me hal t a time 7 solenoid 148 connectedi'by lead 149 to lead 140. This timer is of the pneumatic type of known construction and includes a dashpot 15 1fthe plunger of whichcarriesa delay switch 150. The timer solenoid plungeris separate from the dashpot plungenandactuation of the solenoid hars switch 139 vis again closed, the'energization of solenoid l 'preveuts the opening of switch 150, so that operationbf the torch may be resumed. As previously noted when relayis deenergized it requires operation of n switeh 1 thitesh e the a h g yc e 9f l The e eolding circuit of relay 113 is deyelopedsufiicient Water flow, d switch 117- now can herehath E s e lin thema h l h l sin witqh- .1134 QLQ Mhe hh i s c u of h a n re a. .Tj, .ih d valve 0 hi e hth row i shite s fs i is now manually closed to energize sub- Switch1 23 master relay 125 This causes the following operations: Switch 1251 energizes solenoid valve 72 to start the .iiow'pf oxygen, and energizes and starts timers and 133 Switch 12 energizes the holding circuit of the submaster relay ncluding timer opened switch 129. It sh ul b time?! as after hhlh a' h t s n in r timer 133 closes switch 137 just before timer 130 opens switch f Swi h 1.39 s depr sses y the op m i ely after he closes switch 123 and he holds switch 139 closed so that it is'closed during the short time (about a half .46 a th ehd 6f the hirt se d interval) when bot $Witli 3 an .2 are n. sed position- Shirts the torch operation as follows:

Switch 139 energizes relay and its switch 135b starts the ,powder ieeder motor 64 to begin powder feed more mixer. 'Switch 135:; energizes relay 143, which in turn closes switch "1431 shunting manual switch 123. Switch 139 energizesdelay relay 148 to close switch 159 nd con pletea holding circuit for relay 143 through switch 143a. Timer switch 129 by now has opened, thus making submaster relay 125 responsive to switch 143i), and timer switch 137 has closed, so as to maintain torch switch 139 in a live circuit.

If the torch operator switch 139 is opened, relay 135 is deenergized immediately tostop the powder feed, and the deenergization of solenoid148 releases the dashpot m ni m which, in a predetermined time, opens switch I I'SDf If Qbefore the passage of this predetermined time torch operatorswitch 139is again closed, a solenoid 148 and as relay 135 is energized,-the powderfeed is re- :sumed. However,.if the torch operator switch 139 remains open for the period to which dashpot 151-is set, the dashpot mechanism opens switch 150 to deenergize the holding relay 143 which opens switch 143a to de energize the submaster relay 125 to open the oxygen valve circuit and reset the timers 130, 133, so the opening of switch 137 prevents operation of the torch.

To shut down the whole apparatus, switch 116 is manually opened, thus deenergizing the main relay.

The functions of the control mechanism may be summarized as follows:

(A) To insure an adequate flow of cooling water at the start and during operation of the torch.

(B) To shut down operation of the torch if the cooling water becomes heated to an excessive temperature.

(C) To shut down operation of the torch if the oxygen pressure falls tooclow.

(D) To shut off the oxygen supply if flle dust hopper I pressure becomes excessive.

(E) To insure flow of igniter gas beforeoperation of the torch is begun.

(F) To limit the duration of flow of oxygen if the powder flow is not started within a predetermined time after the flow of oxygen is begun. (G) To limit theduration of flow of powder flow is interrupted. f

'(H) To permit interruption of powder flow and its resumption in a predetermined time after interruption.

We claim:

, 1. A control apparatus for a 'blow torch thatburns metal powder, comprising: a conduit for carrying a mixture of oxygen and metal powder to a blow torch; a blow torch connected to said conduit to receive and burn said mixture; valve means for admitting oxygen into said;. conduit; means for feeding metal powder intosaid conduit; manually-actuated torch control meansoperative,

: after the oxygen valve means is opened, for starting and stopping said metal powder feeding means; and a first I delay means operative, in response to the opening of said oxygen valve means, to prevent said torch control means from starting said metal powder feeding, means until a first predetermined time period has elapsed after the opening of said oxygen valve means.

2. The apparatus of claim 1 including: asecond delay to close said oxygen valve means; and intervening means operative, in response to the start of said metal powder feeding means during said time lag period, to render I said second delay means inoperative.

3. The apparatus of claim 2 wherein: said second delay means also prevents said metal powder feeding means from starting after the end of said time lag period.

4. The apparatus of claim 3 including: a third delay means operative to close said oxygen valve means at imetal powder, comprising: a conduit for carrying a mixture of oxygen and metal powder to a blow torch; a

blow torch connected to said conduit to receive and burn said mixture; valve means for'admitting oxygen into said conduit; means for feeding metal powder into saidconduit; manually-actuated torch control means vfor starting oxygen if the means operative, at the end of a time lag period following the end of said first predetermined time period,

and stopping said metal powder feeding means; and de I lay means operative at the end of a predetermined time period following the openingcof said oxygen valve means, to close said valve means; and'intervening means operaitive, in response to the start of said metal powderfeed-,

render said delay means inoperative.

7. A control apparatus fora blow torch that burns metal powder, comprising: a conduit for carrying a mixture of oxygen and metal powder to a blow torch; a-blow torch connected to said conduit to receive and burn said mixture; valve means for admitting oxygen into said conduit; means for feeding metal powder into said conduit; manually-actuated torch control means for starting and stopping said metal powder feeding means; and delay means operative to close said oxygen valve means at the'end of a predetermined time period following the stopping of said metal powder feeding means.

8. The apparatus of claim 7 wherein: said delay means is rendered inoperative, in response to the starting of said metal powder feeding means during said predetermined time period, to close said valve means.

'9; In a blow torch for burning a metal powder fuel:

a submasterrelay having a plurality of holding circuits;

'means energized by energization of said submasterrelay "to open one of said holding circuits of the submaster relay after a'predetermined time interval; a second time delay means energizedby energization of said submaster 'relay to energize the circuit of said control switch after a ,second predetermined time interval, said first delay means having a lag period over the second delay means; and means operative by said control switch during said lag period to energize another holding circuit of said submaster relay to maintain said submaster relay energized upon opening of said one holding circuit.

.10. Anapparatus as specified in claim 9 wherein said 'means operated by said contro l switch during the lag period includes time delay means, operative when the control switch is in feed means stopping position to hold said last mentioned'means 'in energized position for a predetermined time.

11. In a blow torch as specified in claim 9, a pump for supplying cooling water to the blow torch; a main relay having an actuating circuit including a starting switch; e. main switch'in the submaster relay actuating circuit actuated by the main relay; a holding circuit for said main relay including a main relay operated switch and a -fiow actuated switch held closed by a predetermined minimum flow of water through the pump.

12. A control apparatus for a metal powder burning blow torch comprising: a mixing chamber having an inlet for oxygen'and an outlet for a mixture of oxygen and metalpowder; a blow torch connected to said outlet to receive and burn said mixture; means for feeding metal powder through a powder inlet into the mixing chamber;

"a motor for operating said means; a submaster relay having an actuating circuit including a setting switch; a submaster switch actuated by the submaster relay; a first holding circuit for the submaster relay including a hold- 'for operating said latter switch; a relay for said motor 'having an actuating circuit including said submaster switch, a delayed closing switch and a torch control switch; an operating circuit for said holding relay including a switch operated by said feeder motor relay; a

i delay holding circuit for said holdingrelay including a switch operated by said holding relay and a delay switch;

delay means actuated by energization of the feeder motor relay for setting said delay switch; and delay means anergized by closing of said :submaster switch for actuating said delayed opening switch and delayed closing switch.

References Cited in the file of this patent 10 Yoebels Nov. 21, 1933 MeManamna Feb. 19, 1935 Struckmann Sept. 7, 1948 Linnert Nov. 23, 1948 Chouinard et a1. Dec. 23, 1952 Marshall et a1. June 5, 1956 

